Sharp-interface approach for simulating solid-state dewetting in two dimensions: A Cahn-Hoffman ξ-vector formulation

PHYSICA D-NONLINEAR PHENOMENA

卷:390

Article

Jiang, Wei^1,2  Zhao, Quan³ 

[1] Wuhan Univ, Sch Math & Stat, Wuhan 430072, Hubei, Peoples R China

[2] Wuhan Univ, Computat Sci Hubei Key Lab, Wuhan 430072, Hubei, Peoples R China

[3] Natl Univ Singapore, Dept Math, Singapore 119076, Singapore

关键词: Solid-state dewetting;    Surface energy anisotropy;    Surface diffusion;    Moving contact lines;    Cahn-Hoffman xi-vector;   

DOI  :  10.1016/j.physd.2018.11.003

来源: Elsevier

【 摘 要 】

By using a Cahn-Hoffman xi-vector formulation, we propose a sharp-interface approach for solving so lid state dewetting problems in two dimensions. First, based on the thermodynamic variation and smooth vector-field perturbation method, we rigorously derive a sharp-interface model with weakly anisotropic surface energies, and this model describes the interface evolution which occurs through surface diffusion flow and contact line migration. Second, a parametric finite element method in terms of the xi-vector formulation is proposed for numerically solving the sharp-interface model. By performing numerical simulations, we examine several specific evolution processes for solid-state dewetting of thin films, e.g., the evolution of small islands, pinch-off of large islands and power-law retraction dynamics of semi infinite step films, and these simulation results are consistent with experimental observations. Finally, we also include the strong surface energy anisotropy into the sharp-interface model and design its corresponding numerical scheme via the xi-vector formulation. (C) 2018 Elsevier B.V. All rights reserved.

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